So why is the Daily News virtually the sole survivor among second papers owned by the same company that owns the city’s dominant paper?

Maybe the Daily News is a special case, former publisher Brian Tierney told me Friday in a phone interview. It makes business sense in a way hundreds of casualties over the last 40 years did not.

“Every group [acquiring the Philadelphia papers] has their Chief Financial Officer take a look at it,” Tierney said, with the notion that it probably ought to close. But after that look, each of the four owners over the last six years, has found good reason to keep the Daily News open.

“Number one, it makes money,” said Tierney.

“Number two is the fallacy that all these people would read the Inquirer [if the Daily News did close]. No, they would read the Delaware County Daily Times or the New York Post or Metro.”

When he ran a public relations campaign promoting continued local ownership of the Philadelphia papers, Tierney argued that hedge fund bidders would close the Daily News. Two years after taking control, however, the hedge fund group headed by Alden Global Capital and Angelo, Gordon has yet to pull the trigger.

The sports-heavy, working man’s tabloid picks up additional paying readers the Inquirer misses. For advertisers who want to reach an unduplicated 50,000 — and make a package buy in the two papers — that creates extra ad revenue.

I’ve been told that the Daily News has one of the highest percentages of single copy sales to home delivery among American papers. Some advertisers may want to target just that Daily News readership.

Also when the Audit Bureau of Circulations began offering a measure of readers per copy in the mid-2000s, the Daily News was first among 100 or so participating papers — by a lot. The paper gets around.

I don’t know current editor Larry Platt. But editors I have known — Gil Spencer, Zack Stalberg and Michael Days – have been both highly competent and wily about making the case for the Daily News to top management.

All that said, the Daily News is kind of a 110-year-old among second papers in big cities. The consolidation of morning and evening titles was well under way in the 1970s and pretty well completed by the early 2000s.

I can remember when there was an Atlanta Constitution and an Atlanta Journal in the 1980s, the latter published in the afternoon with a few fresh stories and separate editorial pages that offered different viewpoints.

But in Atlanta, and at most any other hyphenated nameplate you can think of, the papers were not all that different from each other, evening publication was no longer a plus. So the two were simply merged in 2001.

The Daily News moved from an evening to a morning publication a few years ago. In 2009, it became a “branded edition” of the Inquirer. That allows circulation of the two papers to be combined for auditing and sales purposes and puts the Philadelphia papers 15th in the U.S. in daily circulation, with 331,000.

The newsroom consolidation will eliminate the duplication of having two different reporters covering a Phillies game or a City Hall press conference, while maintaining the Daily News’s stable of columnists and commentators.

The move, which eliminates 37 newsroom jobs, is a logical cost saving at a time when the papers and their website are barely profitable and further declines in advertising revenues this year are almost certain. But there is a possible downside. “If they take the voice out of it,” Tierney said, “I don’t know what will happen.”

Meanwhile the Philadelphia Media Network sale drama continues without even a weekend break. Former Governor Ed Rendell told a blogger he met on the street that a group of wealthy and politically connected locals he has formed may not buy the paper after all. A day later he said the group is still in the running, though there may be a second bidder offering more.

So it is an open question who will be deciding the Daily News’s future a year from now or even a month from now.

One more option, short of shuttering the paper, would be to covert it into a re-edited tabloid version of the Inquirer as the Chicago Tribune has done successfully with Red Eye and the Tampa Bay Times with TBT. Those papers are distributed free and defined themselves as they launched, however, a model that might not fit the Daily News.

The anti-Daily News caucus within the company has long argued that the smaller paper diverts resources away from the Inquirer when it too is fighting to hold audience, strengthen digital operations and define a sustainable business model.

That case gains force month by month. My hunch is that the Daily News has a lengthened lease on life, but not an indefinite one.